Rockwell Automation 1747-ASB Remote I/O Adapter - Manual (Page 91)

Publication 1747-UM006B-EN-P - June 2003
Start-Up and Operation 6-5
•
Discrete outputs are held in their last state if hold last state is
selected, or discrete outputs are reset if hold last state is not
selected.
•
The 1747-ASB module does not process any RIO block transfer
writes.
•
The 1747-ASB module sends new input data from its input
modules to the scanner for enabled logical devices.
•
The 1747-ASB module processes RIO block transfer reads for
enabled logical devices.
See page 7-2 for information regarding status codes.
The following table provides specific information concerning how the
inputs and outputs are handled during normal operation and when
communication exceptions occur. Notice that the hold last state
setting makes a difference in the control of the discrete outputs and
how the specialty I/O modules may operate.
IMPORTANT
Reset, adapter reset and reset, adapter decide
commands are always ignored by the 1747-ASB
module when any of its logical devices are inhibited.
1747-ASB Condition Specialty I/O Module Discrete
Outputs
All Inputs
Outputs
SLC State
(1)
Waiting for communications after powerup Not updated Test Cleared Read
Normal running Changing Run Changing Read
Hold last state
selected
(2)
1747-ASB module inhibited
Not updated Run Read Loss of communications
Reset adapter decide
Hold last state
selected or
not selected
(3)
1747-ASB module inhibited
Not updated
Test Cleared Read Loss of communications
Reset adapter decide Updated
Reset adapter reset commands received Updated Test Cleared Read
Major error
(4) Not updated Program/Fault Cleared Not read
Minor error
(5) Not updated Program/Fault Cleared Not read
Expansion chassis power loss Not updated Program/Fault Cleared Not read
(1) This is the 1747-ASB module's operating mode, as compared to an SLC processor. For example, if the SLC state is TEST, the 1747-ASB module
is controlling the specialty I/O modules in the same manner as an SLC processor would in the test mode. Refer to the appropriate SLC
specialty I/O user's manual for more information.
(2) After the 1747-ASB module enters the Run mode.
(3) Before the 1747-ASB module enters the Run mode.
(4) This type of error is usually associated with the 1747-ASB module. Refer to Chapter 7 for more information.
(5) This type of error is usually associated with a configuration error. Refer to Chapter 7 for more information.